checking if a postscript font is installed

Question

I need a way to check if a specific postscript font is installed on a users computer. I have found many ways to check for true type fonts but none seem to work for post script. I have found checking C:\windows\fonts to be unreliable as sometimes the postscript font file is in that directory but not actually installed and available to programs. All the computers are running windows 7 64bit and I'm using c# .net 4.0

Answer 1

So I found two ways of checking this. the first is probably the most reliable but defiantly the most involved

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public class Fonts
{
    private const byte DEFAULT_CHARSET = 1;
    private const byte SHIFTJIS_CHARSET = 128;
    private const byte JOHAB_CHARSET = 130;
    private const byte EASTEUROPE_CHARSET = 238;
    private const byte DEFAULT_PITCH = 0;
    private const byte FIXED_PITCH = 1;
    private const byte VARIABLE_PITCH = 2;
    private const byte FF_DONTCARE = (0 << 4);
    private const byte FF_ROMAN = (1 << 4);
    private const byte FF_SWISS = (2 << 4);
    private const byte FF_MODERN = (3 << 4);
    private const byte FF_SCRIPT = (4 << 4);
    private const byte FF_DECORATIVE = (5 << 4);

    private List<FontFamily> _fonts = new List<FontFamily>();

    public List<FontFamily> FontFamilies
    {
        get { return _fonts; }
        set { _fonts = value; }
    }

    public void GetFonts()
    {
        LOGFONT lf = CreateLogFont("");

        IntPtr plogFont = Marshal.AllocHGlobal(Marshal.SizeOf(lf));
        Marshal.StructureToPtr(lf, plogFont, true);

        int ret = 0;
        try
        {
            //If anyone knows of a better way to get the pointer please let me know
            var pictureBox = new PictureBox();
            var graphic = pictureBox.CreateGraphics();
            var ptr = graphic.GetHdc();

            del1 = new EnumFontExDelegate(callback1);
            ret = EnumFontFamiliesEx(ptr, plogFont, del1, IntPtr.Zero, 0);

            System.Diagnostics.Trace.WriteLine("EnumFontFamiliesEx = " + ret.ToString());

            graphic.ReleaseHdc(ptr);
        }
        catch
        {
            System.Diagnostics.Trace.WriteLine("Error!");
        }
        finally
        {
            Marshal.DestroyStructure(plogFont, typeof(LOGFONT));

        }
    }

    [DllImport("gdi32.dll", CharSet = CharSet.Auto)]
    static extern int EnumFontFamiliesEx(IntPtr hdc,
                            [In] IntPtr pLogfont,
                            EnumFontExDelegate lpEnumFontFamExProc,
                            IntPtr lParam,
                            uint dwFlags);

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public class LOGFONT
    {

        public int lfHeight;
        public int lfWidth;
        public int lfEscapement;
        public int lfOrientation;
        public FontWeight lfWeight;
        [MarshalAs(UnmanagedType.U1)]
        public bool lfItalic;
        [MarshalAs(UnmanagedType.U1)]
        public bool lfUnderline;
        [MarshalAs(UnmanagedType.U1)]
        public bool lfStrikeOut;
        public FontCharSet lfCharSet;
        public FontPrecision lfOutPrecision;
        public FontClipPrecision lfClipPrecision;
        public FontQuality lfQuality;
        public FontPitchAndFamily lfPitchAndFamily;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string lfFaceName;
    }

    public enum FontWeight : int
    {
        FW_DONTCARE = 0,
        FW_THIN = 100,
        FW_EXTRALIGHT = 200,
        FW_LIGHT = 300,
        FW_NORMAL = 400,
        FW_MEDIUM = 500,
        FW_SEMIBOLD = 600,
        FW_BOLD = 700,
        FW_EXTRABOLD = 800,
        FW_HEAVY = 900,
    }
    public enum FontCharSet : byte
    {
        ANSI_CHARSET = 0,
        DEFAULT_CHARSET = 1,
        SYMBOL_CHARSET = 2,
        SHIFTJIS_CHARSET = 128,
        HANGEUL_CHARSET = 129,
        HANGUL_CHARSET = 129,
        GB2312_CHARSET = 134,
        CHINESEBIG5_CHARSET = 136,
        OEM_CHARSET = 255,
        JOHAB_CHARSET = 130,
        HEBREW_CHARSET = 177,
        ARABIC_CHARSET = 178,
        GREEK_CHARSET = 161,
        TURKISH_CHARSET = 162,
        VIETNAMESE_CHARSET = 163,
        THAI_CHARSET = 222,
        EASTEUROPE_CHARSET = 238,
        RUSSIAN_CHARSET = 204,
        MAC_CHARSET = 77,
        BALTIC_CHARSET = 186,
    }
    public enum FontPrecision : byte
    {
        OUT_DEFAULT_PRECIS = 0,
        OUT_STRING_PRECIS = 1,
        OUT_CHARACTER_PRECIS = 2,
        OUT_STROKE_PRECIS = 3,
        OUT_TT_PRECIS = 4,
        OUT_DEVICE_PRECIS = 5,
        OUT_RASTER_PRECIS = 6,
        OUT_TT_ONLY_PRECIS = 7,
        OUT_OUTLINE_PRECIS = 8,
        OUT_SCREEN_OUTLINE_PRECIS = 9,
        OUT_PS_ONLY_PRECIS = 10,
    }
    public enum FontClipPrecision : byte
    {
        CLIP_DEFAULT_PRECIS = 0,
        CLIP_CHARACTER_PRECIS = 1,
        CLIP_STROKE_PRECIS = 2,
        CLIP_MASK = 0xf,
        CLIP_LH_ANGLES = (1 << 4),
        CLIP_TT_ALWAYS = (2 << 4),
        CLIP_DFA_DISABLE = (4 << 4),
        CLIP_EMBEDDED = (8 << 4),
    }
    public enum FontQuality : byte
    {
        DEFAULT_QUALITY = 0,
        DRAFT_QUALITY = 1,
        PROOF_QUALITY = 2,
        NONANTIALIASED_QUALITY = 3,
        ANTIALIASED_QUALITY = 4,
        CLEARTYPE_QUALITY = 5,
        CLEARTYPE_NATURAL_QUALITY = 6,
    }
    [Flags]
    public enum FontPitchAndFamily : byte
    {
        DEFAULT_PITCH = 0,
        FIXED_PITCH = 1,
        VARIABLE_PITCH = 2,
        FF_DONTCARE = (0 << 4),
        FF_ROMAN = (1 << 4),
        FF_SWISS = (2 << 4),
        FF_MODERN = (3 << 4),
        FF_SCRIPT = (4 << 4),
        FF_DECORATIVE = (5 << 4),
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct NEWTEXTMETRIC
    {
        public int tmHeight;
        public int tmAscent;
        public int tmDescent;
        public int tmInternalLeading;
        public int tmExternalLeading;
        public int tmAveCharWidth;
        public int tmMaxCharWidth;
        public int tmWeight;
        public int tmOverhang;
        public int tmDigitizedAspectX;
        public int tmDigitizedAspectY;
        public char tmFirstChar;
        public char tmLastChar;
        public char tmDefaultChar;
        public char tmBreakChar;
        public byte tmItalic;
        public byte tmUnderlined;
        public byte tmStruckOut;
        public byte tmPitchAndFamily;
        public byte tmCharSet;
        int ntmFlags;
        int ntmSizeEM;
        int ntmCellHeight;
        int ntmAvgWidth;
    }
    public struct FONTSIGNATURE
    {
        [MarshalAs(UnmanagedType.ByValArray)]
        int[] fsUsb;
        [MarshalAs(UnmanagedType.ByValArray)]
        int[] fsCsb;
    }
    public struct NEWTEXTMETRICEX
    {
        NEWTEXTMETRIC ntmTm;
        FONTSIGNATURE ntmFontSig;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct ENUMLOGFONTEX
    {
        public LOGFONT elfLogFont;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]
        public string elfFullName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string elfStyle;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string elfScript;
    }

    public delegate int EnumFontExDelegate(ref ENUMLOGFONTEX lpelfe, ref NEWTEXTMETRICEX lpntme, int FontType, int lParam);
    public EnumFontExDelegate del1;

    public int callback1(ref ENUMLOGFONTEX lpelfe, ref NEWTEXTMETRICEX lpntme, int FontType, int lParam)
    {
        try
        {
            FontType fontType;
            if (FontType == 2 || FontType == 4)
            {
                fontType = (ClientTools.Fonts.FontType)FontType;
            }
            else
            {
                fontType = ClientTools.Fonts.FontType.Unknown;
            }

            FontFamilies.Add(new FontFamily(lpelfe.elfFullName, fontType));
        }
        catch (Exception e)
        {
            System.Diagnostics.Trace.WriteLine(e.ToString());
        }
        return 1;
    }

    public static LOGFONT CreateLogFont(string fontname)
    {
        LOGFONT lf = new LOGFONT();
        lf.lfHeight = 0;
        lf.lfWidth = 0;
        lf.lfEscapement = 0;
        lf.lfOrientation = 0;
        lf.lfWeight = 0;
        lf.lfItalic = false;
        lf.lfUnderline = false;
        lf.lfStrikeOut = false;
        lf.lfCharSet = FontCharSet.DEFAULT_CHARSET;
        lf.lfOutPrecision = 0;
        lf.lfClipPrecision = 0;
        lf.lfQuality = 0;
        lf.lfPitchAndFamily = FontPitchAndFamily.FF_DONTCARE;
        lf.lfFaceName = "";


        return lf;
    }
}

public class FontFamily
{
    public string FontName { get; set; }

    public FontType FontType { get; set; }

    public FontFamily(string fontName, FontType fontType)
    {
        FontName = fontName;
        FontType = fontType;
    }
}

public enum FontType
{
    Unknown = 1,
    TrueType = 4,
    PostScript = 2
}

I Borrowed most of this code from another post Enumerating active fonts in C# using DLL call to EnumFontFamiliesEx has me schtumped

The Other way which I have found to be slightly unreliable is the registry key

HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows NT > CurrentVersion > Type 1 Installer > Type 1 Fonts

although this gives you a list of post script fonts. They are not all necessarily installed properly. These keys can point to corrupted fonts that aren't actually installed

I have found the first way of hitting the windows api as the comment suggested works the best